lkml.org 
[lkml]   [2013]   [Nov]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3.5 56/78] can: c_can: Fix RX message handling, handle lost message before EOB
Date
3.5.7.26 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Markus Pargmann <mpa@pengutronix.de>

commit 5d0f801a2ccec3b1fdabc3392c8d99ed0413d216 upstream.

If we handle end of block messages with higher priority than a lost message,
we can run into an endless interrupt loop.

This is reproducable with a am335x processor and "cansequence -r" at 1Mbit.
As soon as we loose a packet we can't escape from an interrupt loop.

This patch fixes the problem by handling lost packets before EOB packets.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
[ luis: backported to 3.5: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
drivers/net/can/c_can/c_can.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 64647d4..91d1b5a 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -764,9 +764,6 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
msg_ctrl_save = priv->read_reg(priv,
&priv->regs->ifregs[0].msg_cntrl);

- if (msg_ctrl_save & IF_MCONT_EOB)
- return num_rx_pkts;
-
if (msg_ctrl_save & IF_MCONT_MSGLST) {
c_can_handle_lost_msg_obj(dev, 0, msg_obj);
num_rx_pkts++;
@@ -774,6 +771,9 @@ static int c_can_do_rx_poll(struct net_device *dev, int quota)
continue;
}

+ if (msg_ctrl_save & IF_MCONT_EOB)
+ return num_rx_pkts;
+
if (!(msg_ctrl_save & IF_MCONT_NEWDAT))
continue;

--
1.8.3.2


\
 
 \ /
  Last update: 2013-11-25 16:01    [W:1.067 / U:0.640 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site